When Lister pulls the first ace out of the pack of cards after being given the luck virus, Kryten states the odds of it happening as being 13 to 1.It is in fact 12 to 1! Couldn't say if Kryten's odds for the other 3 aces are correct though.

There are 13 cards in a suit, Ace is one of them, to pick ANY ace from a standard deck, the odds are 52 (the amount of cards in the deck) to 4 (the amount of Aces in the deck)
52/4=13 Kryten is correct, you are not. not a slip up.

Actually, Colingar is correct. While the odds of pulling an ace from a standard deck of cards is 1 in 13, that is NOT the same as "13 to 1." it is, instead, equivalent to "12 to 1" odds (i.e., the number of possible wrong chances vs. the number of possible right ones).